Abstract: Adjusting a pulse qualification criterion includes receiving a signal representing a plurality of pulses, where the signal is generated in response to detecting light scattered from blood perfused tissue. A characteristic is determined A pulse qualification criterion used for qualifying a pulse is adjusted in accordance with the characteristic. The pulses are evaluated according to the pulse qualification criterion.

Abstract: Adjusting a pulse qualification criterion includes receiving a signal representing a plurality of pulses, where the signal is generated in response to detecting light scattered from blood perfused tissue. A characteristic is determined A pulse qualification criterion used for qualifying a pulse is adjusted in accordance with the characteristic. The pulses are evaluated according to the pulse qualification criterion.

Abstract: In accordance with an embodiment of the present technique, there is provided methods and systems for detecting the presence of venous pulsation by adjusting the sensitivity of a detection algorithm based on a sensor characteristic and/or notifying a caregiver of the presence of venous pulsation by ceasing display of physiological parameters. An exemplary embodiment includes receiving one or more signals from a sensor, the one or more signals corresponding to absorption of light in a patient's tissue; calculating one or more physiological parameters of the patient based on the one or more signals; displaying the patient's physiological parameters; enabling detection of venous pulsation with variable sensitivity based on a location of the sensor; and suspending or terminating the display of the one or more of the patient's physiological parameters when venous pulsation is detected.

Abstract: Methods and systems are provided for deriving and analyzing shape metrics, including skewness metrics, from physiological signals and their derivatives to determine measurement quality, patient status and operating conditions of a physiological measurement device. Such determinations may be used for any number of functions, including indicating to a patient or care provider that the measurement quality is low or unacceptable, alerting a patient or care provider to a change in patient status, triggering or delaying a recalibration of a monitoring device, and adjusting the operating parameters of a monitoring system.

Abstract: In accordance with an embodiment of the present technique, there is provided methods and systems for detecting the location of a sensor and determining calibration algorithms and/or coefficients for calculation of physiological parameters based on the detected location. An exemplary embodiment includes receiving a signal corresponding to absorption of at least one wavelength of light by a patient's tissue, generating a plethysmographic waveform from the signal, determining an identifying characteristic of the plethysmographic waveform, and determining a location of the sensor based on a comparison of the identifying characteristic with at least one defined criterion.

Abstract: A method is provided for determining contact of a sensor with a patient's tissue. The method comprises comparing the intensity of detected light at a first wavelength to a threshold, wherein the first wavelength is not used to determine a physiological characteristic of the patient, and determining if the sensor is in contact with the patient's tissue based on the comparison. In addition, a method is provided for determining the amount of light shunting during operation of the sensor. The method comprises comparing the intensity of detected light at a first wavelength to a threshold, wherein the first wavelength is not used to determine a physiological characteristic of the patient, and determining the amount of light shunting based on the comparison.

Abstract: Methods and systems are provided for determining the oxygen saturation of a region in a patient's body using photoacoustic spectroscopy techniques. One embodiment includes determining an interrogation region, or a region in a patient to be monitored, and using a photoacoustic sensor to emit modulated light in the interrogation region. The modulated light may be absorbed by different absorbers, such as oxygenated hemoglobin and deoxygenated hemoglobin, in the interrogation region. The absorbed light results in an acoustic response which is detected by the photoacoustic sensor. Based on a non-pulsatile component of the acoustic response, the regional oxygen saturation at the interrogation region is calculated.

Abstract: Adjusting a pulse qualification criterion includes receiving a signal representing a plurality of pulses, where the signal is generated in response to detecting light scattered from blood perfused tissue. A characteristic is determined. A pulse qualification criterion used for qualifying a pulse is adjusted in accordance with the characteristic. The pulses are evaluated according to the pulse qualification criterion.

Abstract: In accordance with an embodiment of the present technique, there is provided methods and systems for detecting the presence of venous pulsation by adjusting the sensitivity of a detection algorithm based on a sensor characteristic and/or notifying a caregiver of the presence of venous pulsation by ceasing display of physiological parameters. An exemplary embodiment includes receiving one or more signals from a sensor, the one or more signals corresponding to absorption of light in a patient's tissue; calculating one or more physiological parameters of the patient based on the one or more signals; displaying the patient's physiological parameters; enabling detection of venous pulsation with variable sensitivity based on a location of the sensor; and suspending or terminating the display of the one or more of the patient's physiological parameters when venous pulsation is detected.

Abstract: In accordance with an embodiment of the present technique, there is provided methods and systems for detecting the location of a sensor and determining calibration algorithms and/or coefficients for calculation of physiological parameters based on the detected location. An exemplary embodiment includes receiving a signal corresponding to absorption of at least one wavelength of light by a patient's tissue, generating a plethysmographic waveform from the signal, determining an identifying characteristic of the plethysmographic waveform, and determining a location of the sensor based on a comparison of the identifying characteristic with at least one defined criterion.

Abstract: A sensor may be adapted to reduce signal artifacts by deflecting the effects of outside forces and sensor motion. A sensor is provided with a rigid annular structure adapted to reduce the effect of motion of a sensor emitter and/or detector. Further, a method of deflecting or minimizing outside forces and sensor motion is also provided.

Abstract: A method and an apparatus for measuring a physiological parameter, functioning based on obtaining a first signal derived from electromagnetic energy transmitted through a tissue portion at a first wavelength, the first signal including a signal portion corresponding with motion-related events and a signal portion corresponding with arterial pulsation events, where at the first wavelength water is a dominant absorber of electromagnetic energy in the tissue portion; obtaining a second signal derived from electromagnetic energy transmitted through a tissue portion at a second wavelength, the second signal including a signal portion corresponding with motion-related events and a signal portion corresponding with arterial pulsation events, where at the second wavelength hemoglobin is a dominant absorber of electromagnetic energy in the tissue portion; and combining the first signal and the second signal to generate a combined plethysmograph signal, such that the combined signal has a signal portion corresponding w

Abstract: Methods and systems for detecting venous pulsation are provided. In one embodiment, a metric of the pulse shape of one or more plethysmographic signals is derived and the presence of venous pulsation is detected based on the metric of pulse shape. Examples, of metrics of pulse shape include a skew metric and a ratio of a minima-to-maxima time over a pulse period interval. In an exemplary embodiment, the presence of venous pulsation is detected based on a metric of the pulse shape of one or more plethysmographic signals and on a phase comparison of the plethysmographic signals.

Abstract: A system and method are provided for determining tissue hydration. Specifically, in accordance with one aspect of the present invention there is provided a method for determining tissue hydration. The method includes detecting electromagnetic radiation scattered and reflected from the living tissue and using the detected electromagnetic radiation to determine spectral absorption bandwidth. The method also includes correlating the spectral absorption bandwidth to a tissue hydration index.

Abstract: Methods and systems for calculating body fluid metrics are provided. In accordance with an exemplary embodiment of the present technique, there is provided a method for calculating body fluid metrics by acquiring an absorbance spectrum of a subject's tissue over a range of near-infrared light, performing a multi-linear regression of the absorbance spectrum of the subject's tissue in relation to absorbance spectra of tissue constituents, and calculating body fluid metrics based on the results of the multi-linear regression. A system is provided having a sensor for emitting the light into the subject's tissue and detecting reflected, scattered, or transmitted light, a spectrometer for processing the detected light and generating the absorbance spectrum of the subject's tissue, memory for storing absorbance spectra of the tissue constituents and a multi-linear regression model, and a processor for performing the multi-linear regression and calculating the body fluid metrics.

Abstract: A method and system for measuring a physiological parameter, comprising collecting a first absorbance at a first wavelength, chosen to be primarily absorbed by water; collecting a second absorbance at a second wavelength, chosen to be primarily absorbed by hemoglobin; and combining the first signal and the second signal to generate a combined plethysmograph signal which is proportionate lower in noise caused by motion-related interference.

Abstract: A sensor may be placed on a patient to obtain physiological measurements. The application of the sensor on the patient may start a timer set to run for a given time interval. If the sensor is repositioned before the interval is expired, the timer is reset. If the time expires without the sensor being repositioned, a caregiver is prompted to reposition the sensor.

Abstract: A system configured to provide feedback regarding fluid parameters in the skin and/or compartments of an individual to facilitate early diagnosis of skin wounds and compartment syndromes.

Abstract: A sensor may be adapted to reduce signal artifacts by deflecting the effects of outside forces and sensor motion. A sensor is provided with a rigid annular structure adapted to reduce the effect of motion of a sensor emitter and/or detector. Further, a method of deflecting or minimizing outside forces and sensor motion is also provided.

Abstract: The present disclosure provides systems, devices, and/or methods for assessing body fluid-related metrics and/or changes therein. The disclosure further provides systems, devices, and/or methods for correlating body fluid-related metrics in a particular tissue with the corresponding whole-body metric. The disclosure also provides, systems, devices, and/or methods for assessment of such metrics to facilitate diagnosis and/or therapeutic interventions related to maintaining and/or restoring body fluid balance.